Thin-client diagramming tools provide a number of advantages over traditional thick-client design tools but are challenging to build. We describe an extension to a thick-client meta-tool that allows any specified diagram editor to be realised as a thin-client tool. A set of server-side components interact with the thick-client tool to generate GIF or SVG diagrams for both display and editing in a conventional web browser. We describe the motivation for our work, our novel architecture, illustrate and discuss interaction issues with the generated diagrams, and describe evaluations of the effectiveness of our approach..